Package org.uma.evolver.algorithm.base.nsgaii

Class BinaryNSGAII

java.lang.Object

org.uma.evolver.algorithm.base.nsgaii.BaseNSGAII<org.uma.jmetal.solution.binarysolution.BinarySolution>

org.uma.evolver.algorithm.base.nsgaii.BinaryNSGAII

All Implemented Interfaces:

BaseLevelAlgorithm<org.uma.jmetal.solution.binarysolution.BinarySolution>

public class BinaryNSGAII
extends BaseNSGAII<org.uma.jmetal.solution.binarysolution.BinarySolution>

A configurable implementation of the Non-dominated Sorting Genetic Algorithm II (NSGA-II) specifically designed for binary-encoded optimization problems.

This class extends the base BaseNSGAII implementation to handle binary-encoded solutions, providing specialized support for binary-specific operations and parameters.

Key features include:

• Support for binary-encoded solution spaces
• Configurable genetic operators through the parameter space
• Automatic handling of solution encoding/decoding
• Integration with JMetal's binary problem interface

Example usage:

 // Create a binary problem instance
 BinaryProblem problem = new MyBinaryProblem();
 
 // Configure the algorithm
 int populationSize = 100;
 int maxEvaluations = 25000;
 ParameterSpace parameterSpace = new ParameterSpace();
 // Configure parameter space with desired operators and parameters
 
 // Create and run the algorithm
 BinaryNSGAII algorithm = new BinaryNSGAII(problem, populationSize, maxEvaluations, parameterSpace);
 algorithm.run();
 
 // Get results
 List<BinarySolution> population = algorithm.result();
 

The algorithm automatically configures non-configurable parameters such as the number of bits in the solution based on the problem definition. For binary problems, the total number of bits is automatically determined from the problem instance.

Since:

version

Author:

Your Name (your.email@example.com)

See Also:

• BaseNSGAII
• BinaryProblem
• BinarySolution
• MutationParameter

Field Summary

Fields inherited from class org.uma.evolver.algorithm.base.nsgaii.BaseNSGAII

densityEstimator, externalArchive, maximumNumberOfEvaluations, offspringPopulationSize, parameterSpace, populationSize, problem, ranking, rankingAndCrowdingComparator

Constructor Summary

Constructors

Constructor	Description
BinaryNSGAII(int populationSize, ParameterSpace parameterSpace)	Constructs a new instance of BinaryNSGAII with the specified population size and parameter space.
BinaryNSGAII(org.uma.jmetal.problem.Problem<org.uma.jmetal.solution.binarysolution.BinarySolution> problem, int populationSize, int maximumNumberOfEvaluations, ParameterSpace parameterSpace)	Constructs a fully configured BinaryNSGAII instance ready for execution.

Method Summary

Modifier and Type	Method	Description
BaseLevelAlgorithm<org.uma.jmetal.solution.binarysolution.BinarySolution>	createInstance(org.uma.jmetal.problem.Problem<org.uma.jmetal.solution.binarysolution.BinarySolution> problem, int maximumNumberOfEvaluations)	Creates and returns a new instance of BinaryNSGAII configured for the specified problem.
protected void	setNonConfigurableParameters()	Configures non-configurable parameters based on the problem's characteristics.

Methods inherited from class org.uma.evolver.algorithm.base.nsgaii.BaseNSGAII

build, createEvaluation, createExternalArchive, createInitialSolutions, createReplacement, createSelection, createTermination, createVariation, parameterSpace

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface org.uma.evolver.algorithm.base.BaseLevelAlgorithm

parse

Constructor Details

BinaryNSGAII

public BinaryNSGAII(int populationSize,
 ParameterSpace parameterSpace)

Constructs a new instance of BinaryNSGAII with the specified population size and parameter space.

Note: This creates a partially configured instance. The createInstance(Problem, int) method must be called with a problem instance before the algorithm can be used.

Parameters:

populationSize - the size of the population to be used in the algorithm. Must be positive.

parameterSpace - the parameter space containing configuration parameters for the algorithm. Must not be null.

Throws:

IllegalArgumentException - if populationSize is not positive or parameterSpace is null

BinaryNSGAII

public BinaryNSGAII(org.uma.jmetal.problem.Problem<org.uma.jmetal.solution.binarysolution.BinarySolution> problem,
 int populationSize,
 int maximumNumberOfEvaluations,
 ParameterSpace parameterSpace)

Constructs a fully configured BinaryNSGAII instance ready for execution.

Parameters:

problem - the binary problem to be solved. Must implement the BinaryProblem interface.

populationSize - the size of the population. Must be a positive integer.

maximumNumberOfEvaluations - the evaluation budget for the algorithm. The algorithm will terminate once this number of evaluations is reached.

parameterSpace - the parameter space containing configuration parameters for the algorithm.

Throws:

IllegalArgumentException - if any parameter is invalid (null or non-positive values where required)

ClassCastException - if the provided problem does not implement BinaryProblem

Method Details

createInstance

public BaseLevelAlgorithm<org.uma.jmetal.solution.binarysolution.BinarySolution> createInstance(org.uma.jmetal.problem.Problem<org.uma.jmetal.solution.binarysolution.BinarySolution> problem,
 int maximumNumberOfEvaluations)

Creates and returns a new instance of BinaryNSGAII configured for the specified problem.

This method implements the factory method pattern, allowing the creation of algorithm instances with the same configuration but potentially different problems or evaluation limits.

Parameters:

problem - the binary optimization problem to solve. Must not be null.

maximumNumberOfEvaluations - the maximum number of evaluations allowed for the new instance. Must be positive.

Returns:

a new, fully configured instance of BinaryNSGAII

Throws:

IllegalArgumentException - if problem is null or maximumNumberOfEvaluations is not positive

setNonConfigurableParameters

protected void setNonConfigurableParameters()

Configures non-configurable parameters based on the problem's characteristics.

This method is automatically called during algorithm initialization to set up parameters that depend on the specific problem instance, such as the total number of bits in the solution. It configures mutation parameters based on the problem's binary encoding.

Specified by:

setNonConfigurableParameters in class BaseNSGAII<org.uma.jmetal.solution.binarysolution.BinarySolution>